Research efforts are aimed at understanding the role played by electrode surface composition and structure in determining and controlling the electrochemical reactivity of species present at electrode-solution interfaces. Current research projects study fundamental aspects of electrocatalysis and of biosensor technologies. The studies combine the use of XPS, AES, LEDD, TDMS, Thin  Layer and classical electrochemical.

Synthesis and characterization of fullerene  transition metal complexes. Electronic and geometric structure of fullerene  transition metal complexes and the relationship of their structure with the complexes chemical reactivities. Integration of high school biology, chemistry, mathematics and physics using calculator-based laboratory technology.

Develop advanced spectroscopic and spectrometric techniques for the characterization and quantification of pharmaceutically relevant compounds. Develop new analytical schemes for the detection of pesticides, pharmaceutical and personal care products and other aromatic contaminants in the environment. Study the impact of persisting oprganic contaminants on human health. Characterization of bimolecular systems of pharmaceutical and environmental interest.

Optimization of CG-MS and CG-FID tropical analysis of thermally labile essential oils in plants. Development of the right analytical methodology as a fundamental prerequisite to assess the biosynthetic capacity of plant cells and tissues cultured in vitro. Methods developments of the analysis of samples of environmental origin.

Isolation and characterization of oxidative enzymes from fungi; study of role of oxidative enzyme on fungal pathogenicity. Isolation and inhibition studies of Histidine Decarboxylase from microorganisms which contaminate fish and dairy products. Study of the effects of antioxidants on the development of rancidity in frozen Tilapia.

Work on my laboratory focuses on mid  infrared FTIR spectroscopy of transient species and reaction intermediates, mainly radicals using Matrix-isolation. We are also interested in photochemical reactions and reactions dealing with semiconductor materials.

Research interest: Structure and function relationships in hemeproteins, like the unique hemoglobin I from Lucina pectinata. For example, using “site directed mutagenesis” we tailor the structure of this hemoglobin. Its chemical structure is then studied by Fourier Transform infrared, resonance Raman vibrational analysis, and NMR spectroscopies. This is followed by the kinetic study of the reaction between hemoglobin and ligands (for example, O2, CO, NO, and H2S) using time  resolved (pump and probe) infrared and resonance Raman techniques. Ultrafast geminate chemical dynamics are studied also in our laboratory using time - resolved (pump and probe) picosecond and femtosecond spectroscopy.

Education Interest: Development and implementation of a coherent link between pre-college education and the University (K-12 Outreach Programs University Science Programs). To accomplish this goal I developed the Science Shows and GLOBE programs in Puerto Rico.

Meléndez’s research work entails the design of metal-based drugs and organometallic biosensors. New metallocene drugs which target specific tumors and receptors are developed as tools for treating cancers.

Studies to understand protein-ligand, protein-protein and protein-lipid interactions that have direct clinical relevance following an approach used that is multidisciplinary in nature involving molecular biology, biochemistry biophysics and molecular modeling.

Organic Synthesis and Medicinal Chemistry. Chemotherapeutic approach to the treatment of tumors and the chemistry involved in the synthesis of those ligands. Methodology development for the synthesis of useful intermediates to be used in the construction of novel chemotherapeutic drug.

The analyses and structural studies of macromolecules, natural products, organic and inorganic molecules, utilizing X-ray crystallography as the main analytical tool. The primary targets will be proteins, inhibitor-protein and protein-protein complexes, involved in the complex blood coagulation process. Proteins and complexes of other cell signaling and metabolic processes, will be studied as well. The aim is to study their mechanism(s) of action and structural/activity relationships, based on the X-ray model obtained. Molecules are crystallized; data is collected and analyzed; and the structure is modeled into the electron density maps and finally analyzed in detail.

Synthesis of oligopeptides containing one or more aromatic amino acids; study of small molecule-nucleic acid interactions; synthesis of oligopeptides with unusual amino acids, synthesis of oligopeptide analogs.

In vitro evaluation of decoctions from plants of reputed ethnopharmaceutical activity to treat kidney stones disease. The project includes measurements of free and complex Ca+2 in solution, dissolution of calcium oxalate or calcium phosphate by plant decoctions, and inhibition of crystal or stone growth by plant extracts.

Development of near infrared spectroscopic methods for use in the pharmaceutical industry. Development of analytical methods to study interactions between excipients in solid oral dosage forms and tablet surfaces. Continuing Education and Professional/Personal Development of Chemists, and use of polarized light microscopy in chemical education.